Year: 2023
Type: preprint
Abstract: Starburst (SB) galaxies are a rare population of galaxies with star formation rates (SFRs) greatly exceeding those of the majority of star-forming galaxies with similar stellar mass. It is unclear whether these bursts are the result of either especially large gas reservoirs or enhanced efficiencies in converting gas into stars. Tidal torques resulting from gas-rich galaxy mergers are known to enhance the SFR by funneling gas towards the centre. However, recent theoretical works show that mergers do not always trigger a SB and not all SB galaxies are interacting systems, raising the question of what drives a SB. We analyse a large sample of SB galaxies and a mass- and redshift-matched sample of control galaxies, drawn from the FIREbox cosmological volume at z=0-1. We find that SB galaxies have both larger molecular gas fractions and shorter molecular depletion times than control galaxies, but similar total gas masses. Control galaxies evolve towards the SB regime by gas compaction in their central regions, over timescales of about 70 Myr, accompanied by an increase in the fraction of ultra-dense and molecular gas. The driving mechanism behind the SB varies depending on the mass of the galaxy. Massive (Mstar > 1e10 Msun) galaxies undergoing intense, long-lasting SBs are mostly driven by galaxy interactions. Conversely, SBs in non-interacting galaxies are often triggered by a global gravitational instability, that can result in a breathing mode in low-mass galaxies.
Source: arXiv (Cornell University)
Institutions: University of Zurich, Pomona College, Flatiron Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Partnership for Advanced Computing in Europe AISBL, Barcelona Supercomputing Center, Universität Zürich, Centro Svizzero di Calcolo Scientifico, National Supercomputing Centre Singapore
Awards: The baryonic cycle in galaxies from Cosmic Dawn to Cosmic Noon, G1200789703, Computation for the Endless Frontier, G2808148935, G5941523914, G6837874440, AstroSignals: A New Window on the Universe, with the New Generation of Large Radio-Astronomy Facilities, Aiming for the Parsec Scale - The Rise of Massive Galaxies and their Supermassive Black holes
OpenAlex ID: W4386875257